“Huguenots” was the name given to French Protestants from the 16th century onwards. They were persecuted by the ruling Catholics, especially after the Massacre of St Bartholomew’s Day in 1572 and the revocation of the Edict of Nantes by Louis XIV in 1685.
There followed an exodus of French Protestants, to neighbouring Protestant countries like the Netherlands, to the New World and South Africa, and across the Channel to England. It is estimated that around 50,000 came to England, although many of them moved on to other countries.
They were generally welcomed by the community and the clergy. According to the Guide to the Parish and non-Parochial registers of Devon & Cornwall 1538-1837, the Huguenot congregations in Devon were “more numerous than in any other English county outside London and its vicinity, probably due to local diocesan sympathy”
In 1686 they started a “conformist” congregation (ie it followed the Church of England prayer book) at St Olaves church on Fore Street. Interestingly, the church was founded by Gytha, mother of King Harold, and named after a Viking saint.
In 1715, it was recorded that St Olaves had a congregation of 120, under the minister Andrew Majendie. Services were conducted in French, and the church was popularly known as the French church.
Eventually of course, as with so many other migrant populations, the Huguenots lost their cultural identity and were absorbed into the gene pool. Surnames survive, including du Maurier, de Morgan and Olivier.
Exeter Memories have a good page on St Olaves.